Cant find the information of register MPU6050_RA_BANK_SEL

Hi all,the register map of mpu6050 doesn't show the address of the reigster MPU6050_RA_BANK_SEL ,also no any information of it . But it is used in MPU6050_6Axis_MotionApp20.h ,and I dont understand the dmpMemory either.

Could anyone explain it?

Thanks.

Invense made the (bad) decision to keep many things a secret when they introduced the MPU-6050. Register 0x6D was undocumented. Someone reverse-engineered the 'dmp' and that is how the firmware of the MPU-6050 was known. It turned out that the 'dmp' uses many undocumented registers. The i2devlib uses that reverse-engineered firmware.

Later Invense gave more documentation for the use of the 'dmp', but they never made a new datasheet.

If I am right ,the dmp has its own flash memory(almost 2k bytes)?

I guess I should find out these secret documents of the dmp.